Generally, a room designed to shield against ionizing radiation e.g.: X-Rays/Gamma Rays will require a continuous lead barrier, in the walls to a height of 2100 mm or higher that is designed to attenuate the ionizing radiation being emitted from the imaging equipment installed in the room.
Generally the current method used in the attempt to provide a lead radiation shielding barrier is to construct a metal stud partition, installing to one side of the gyproc, a layer of sheet lead laminated to the back face. The laminated gyproc's manufacturers' installation instructions direct the installer to screw the laminated gyproc to the studs through predrilled fastening holes, then countersink all of the fastening screw heads, minimum 3 mm, through the face paper allowing for attachment of lead screw caps over, screwing the laminated gyproc to the studs through pre-drilled fastening holes. This act of countersinking the screws into the gypsum may destroy the structural integrity of the gypsum board.
Additionally, once the screws are countersunk in the gypsum board, lead screw caps or buttons are hammered into position over every screw. This may be costly in both construction time and labour cost. Many caps/buttons are not properly installed or not installed at all allowing radiation leaks. Moreover in the angular incidence there is not enough steel in the drywall screws to provide attenuation equivalent to that provided by the lead.
Furthermore, in addition to lead screw caps, a strip of sheet lead equaling the attenuating capability of the lead laminated gypsum board must be installed between the leaded face of the gypsum board and the face of the metal stud where two or more sheets of gypsum board are butted together, to prevent leakage at this seam. This may be costly in both construction time and labour cost. Many joining strips are left out allowing large gaps for ionizing radiation leaks.
Other leak-proof barrier systems were allegedly created without the lead screw caps being installed over every screw or the strip of sheet lead designed to provide radiation shielding not being installed at the seams. U.S. Pat. No. 6,550,203 to Little suggests that when a lead barrier plate is installed which extends beyond the flanges of the metal stud, the countersunk holes and the lead strip added at the juncture where two or more sheets of lead laminated gypsum board abut, are no longer required.
U.S. Pat. No. 4,038,553 to McCullagh discloses a clamping apparatus having a stud capturing portion and a stud facing portion bolted together to clamp a lead sheet.
All previously described methods of creating a radiation leak proof lead barrier systems require extensive time consuming skilled labour to install.
In addition, the integrity of the lead in some previously described systems is compromised by requiring fixed sizes of components that are not adjustable to accommodate different thicknesses or weights of lead.
In addition, the lead attachment method described in some previously described systems is compromised by way of the system itself being difficult to access, difficult to install or too unclear for installers during installation procedures.
In addition, the lead attachment method described in some previously described systems is compromised by way of the system itself failing to meet the guidelines for the structural support of lead sheets set out by the International Lead Association (London).
In addition, the installation of any electrical devices, such as for example, switches or receptacles; or plumbing fixtures, such as water supply and drainage lines, that are required to be installed in walls, would require either damaging or penetrating the lead barrier or would not allow the barrier to be installed at all.